Financial aid standards vary between hospitals, and some are more eager to provide assistance, says Jason McNichol, an advocate who helped Casey get bills written off. He says patients' financial applications often get "lost" and their bills sent to a collection agency.

In return for caring for people like Casey, Oregon's tax-exempt hospitals -- both not-for-profit and government-affiliated hospitals like Oregon Health & Science University -- receive significant benefits:

money can be borrowed at a discounted rate, a privilege worth millions;

tax exemptions from state and federal corporate and capital gains taxes, and property taxes collected by counties;

any contributions to them are tax-deductible, which encourages giving.

In Multnomah County alone, not-for-profit hospitals were spared an estimated $33 million in property taxes last year, according to the assessor's office. Exact figures aren't available, but their state and federal taxes avoided were far more.

Hospitals have made the most of those advantages. Legacy Health's umbrella nonprofit built assets from $270 million in 2005 to more than $1 billion as of 2009, its latest tax return available. Providence Health and Services of Oregon saw assets balloon from $1 billion in 2002 to $2.4 billion in 2010.

Acquisitions by hospitals are a major reason municipal tax bases are "under siege," according to the November issue of Governing Magazine.

The Illinois Supreme Court in 2010 stripped a nonprofit hospital of its tax exemption over its stingy charity care and billing practices. John Colombo, a professor at the University of Illinois College of Law who tracked the case, thinks nonprofits should prove their community benefit before they get tax breaks, not after. Looking at nonprofit hospitals today, "nobody would think they were charities: they're big business."

At least one person in Congress agrees. In the U.S. Senate, Republican Chuck Grassley of Iowa once called for private nonprofit hospitals to provide a minimum of 5 percent charity care.

"The devil is in the details," says Legacy's Eager, but he, too, likes a minimum --including for government-affiliated tax-exempt hospitals like OHSU.

Trending down

Charity care numbers aren't perfect because hospital fiscal years vary, and Kaiser Sunnyside doesn't report financial numbers to the state. The state hasn't finalized its 2011 community benefit reports. But the steady drop from 4.3 to 4 percent statewide is clear.

Other hospitals don't like the idea of minimums. OHSU last year provided charity care worth 2.9 percent of its net revenues.

OHSU's Lawrence Furnstahl says the numbers are deceptive because about 28 percent of the university's patient load is on Medicaid -- care that is not free, but subsidized by the hospital because reimbursements are so low. That Medicaid caseload is well above the state average.

"There's no single metric that says 'Well, yeah this is the perfect measure,'" Furnstahl said. "Every (hospital's) role is different in the community."

Priscilla Lewis, who oversees charity care for Providence, agrees. The Seattle-based health network, whose charitable mission focuses on care of the "poor and vulnerable," has seen its charity care spending drop significantly in the Portland area, from 5.5 to 4.2 percent of revenues between 2009 and 2011. She says nonprofit hospitals prove their worth in other ways.

Oregon's community benefit reporting system reflects that point of view.

In 2007, Oregon lawmakers required better reporting not just of hospitals' charity care, but other activities like public health education, research and support for Medicare and the Medicaid-funded Oregon Health Plan.

Hospitals prefer the combined figure, because charity care "doesn't paint the whole picture," said Andy Van Pelt, chief operating officer of the Oregon Association of Hospitals and Health Systems. "It's one piece of a much larger pie."

Community benefit figures show most hospital systems in the region providing benefits worth about 16 percent of their revenue, a proportion holding mostly steady since 2009.

The Oregon reporting law was one of the nation's earliest. In Texas, lawmakers required hospitals provide 4 percent of their budget in charity care and other help for the poor, and Illinois recently required that charity care exceed property taxes.

However, the federal health reform that kicks in 2014 is expected to make charity care even less common as the number of uninsured is expected to drop sharply.

But under the new law, hospitals will be asked to submit plans for how they will improve their community's overall health.

That doesn't satisfy Paul Chalmers of Umatilla. He is one of several Oregon county assessors who've increasingly questioned hospital tax breaks. "There's a lot of organizations that do a lot of good things," he says – but many of them are not tax-exempt.

And it sounds like 2014 could make the standards for hospitals even murkier, he says: "There's no clear barometer that says hospitals should or should not be exempt. We still don't have clarity."